The present invention relates generally to the field of orthodontics, and more particularly to tooth attachments for engaging a dental repositioning appliance, the attachments having improved or optimized design parameters and/or geometries customized to the individual patient and/or for improved application of a desired force system selected to elicit the identified tooth movement.
An objective of orthodontics is to move a patient's teeth to positions where function and/or aesthetics are optimized. Traditionally, appliances such as braces are applied to a patient's teeth by an orthodontist or dentist and the set of braces exerts continual force on the teeth and gradually urges them toward their intended positions. Over time and with a series of clinical visits and adjustments to the braces, the orthodontist adjusts the appliances to move the teeth toward their final destination.
More recently, alternatives to conventional orthodontic treatment with traditional affixed appliances (e.g., braces) have become available. For example, systems including a series of preformed aligners have become commercially available from Align Technology, Inc., Santa Clara, Calif., under the tradename Invisalign® System. The Invisalign® System is described in numerous patents and patent applications assigned to Align Technology, Inc. including, for example in U.S. Pat. Nos. 6,450,807, and 5,975,893, as well as on the company's website, which is accessible on the World Wide Web (see, e.g., the url “align.com”). The Invisalign® System includes designing and/or fabricating multiple, and sometimes all, of the aligners to be worn by the patient before the aligners are administered to the patient and used to reposition the teeth (e.g., at the outset of treatment). Often, designing and planning a customized treatment for a patient makes use of computer-based 3-dimensional planning/design tools, such as software technology available from Align Technology, Inc. The design of the aligners can rely on computer modeling of a series of planned successive tooth arrangements, and the individual aligners are designed to be worn over the teeth and elastically reposition the teeth to each of the planned tooth arrangements.
Orthodontic appliances and systems often make use of tooth attachments or components bonded on a surface of a tooth in order to elicit a desired tooth movement. Appliances, in general, apply force and/or torque on a tooth crown to move teeth, with the applied force typically normal with respect to the surface of a tooth or attachment positioned on the tooth. Currently, orthodontic systems typically use a number of generic or standard attachments to accomplish orthodontic tooth movement. A tooth movement may be identified, and then a generic or standard attachment is selected for use in connection with a repositioning appliance. Selection and positioning of the attachment is typically accomplished based on clinical experience or at the discretion of the treating professional. Unfortunately, such current approaches have proven in some cases to be of limited success as the selected attachment configurations and/or positioning on the tooth may fail to deliver optimal or even sufficient application of forces so as to elicit the desired tooth movement. In some instances, actual forces applied to the teeth are not as initially expected, and may result in lack of movement or incorrect and unwanted tooth movement. Current tooth attachments used for rotation have the same shape and position for all patients and teeth undergoing movement with a rotation component. Due to the individual morphology of teeth and composite movements, the performance of such attachments may not be optimal for all patients.
Accordingly, improved techniques and orthodontic systems are needed for designing and providing more effective tooth movement forces to the teeth during orthodontic treatment using tooth attachments, and reducing unwanted tooth movements.